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BinaryWriter Class
 
System_CAPS_noteNote

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Writes primitive types in binary to a stream and supports writing strings in a specific encoding.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

SystemObject
  System.IOBinaryWriter

[SerializableAttribute]
[ComVisibleAttribute(true)]
public class BinaryWriter : IDisposable
[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class BinaryWriter : IDisposable
[<SerializableAttribute>]
[<ComVisibleAttribute(true)>]
type BinaryWriter = 
    class
        interface IDisposable
    end
<SerializableAttribute>
<ComVisibleAttribute(True)>
Public Class BinaryWriter
	Implements IDisposable
NameDescription
System_CAPS_protmethod BinaryWriter

Initializes a new instance of the BinaryWriter class that writes to a stream.

System_CAPS_pubmethod BinaryWriter

Initializes a new instance of the BinaryWriter class based on the specified stream and using UTF-8 encoding.

System_CAPS_pubmethod BinaryWriter

Initializes a new instance of the BinaryWriter class based on the specified stream and character encoding.

System_CAPS_pubmethod BinaryWriter

Initializes a new instance of the BinaryWriter class based on the specified stream and character encoding, and optionally leaves the stream open.

NameDescription
System_CAPS_pubproperty

Gets the underlying stream of the BinaryWriter.

NameDescription
System_CAPS_pubmethod Close

Closes the current BinaryWriter and the underlying stream.

System_CAPS_pubmethod Dispose

Releases all resources used by the current instance of the BinaryWriter class.

System_CAPS_protmethod Dispose

Releases the unmanaged resources used by the BinaryWriter and optionally releases the managed resources.

System_CAPS_pubmethod Equals

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethod Finalize

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethod Flush

Clears all buffers for the current writer and causes any buffered data to be written to the underlying device.

System_CAPS_pubmethod GetHashCode

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethod MemberwiseClone

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethod Seek

Sets the position within the current stream.

System_CAPS_pubmethod ToString

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethod Write

Writes a one-byte Boolean value to the current stream, with 0 representing false and 1 representing true.

System_CAPS_pubmethod Write

Writes an unsigned byte to the current stream and advances the stream position by one byte.

System_CAPS_pubmethod Write

Writes a byte array to the underlying stream.

System_CAPS_pubmethod Write

Writes a region of a byte array to the current stream.

System_CAPS_pubmethod Write

Writes a Unicode character to the current stream and advances the current position of the stream in accordance with the Encoding used and the specific characters being written to the stream.

System_CAPS_pubmethod Write

Writes a character array to the current stream and advances the current position of the stream in accordance with the Encoding used and the specific characters being written to the stream.

System_CAPS_pubmethod Write

Writes a section of a character array to the current stream, and advances the current position of the stream in accordance with the Encoding used and perhaps the specific characters being written to the stream.

System_CAPS_pubmethod Write

Writes a decimal value to the current stream and advances the stream position by sixteen bytes.

System_CAPS_pubmethod Write

Writes an eight-byte floating-point value to the current stream and advances the stream position by eight bytes.

System_CAPS_pubmethod Write

Writes a two-byte signed integer to the current stream and advances the stream position by two bytes.

System_CAPS_pubmethod Write

Writes a four-byte signed integer to the current stream and advances the stream position by four bytes.

System_CAPS_pubmethod Write

Writes an eight-byte signed integer to the current stream and advances the stream position by eight bytes.

System_CAPS_pubmethod Write

Writes a signed byte to the current stream and advances the stream position by one byte.

System_CAPS_pubmethod Write

Writes a four-byte floating-point value to the current stream and advances the stream position by four bytes.

System_CAPS_pubmethod Write

Writes a length-prefixed string to this stream in the current encoding of the BinaryWriter, and advances the current position of the stream in accordance with the encoding used and the specific characters being written to the stream.

System_CAPS_pubmethod Write

Writes a two-byte unsigned integer to the current stream and advances the stream position by two bytes.

System_CAPS_pubmethod Write

Writes a four-byte unsigned integer to the current stream and advances the stream position by four bytes.

System_CAPS_pubmethod Write

Writes an eight-byte unsigned integer to the current stream and advances the stream position by eight bytes.

System_CAPS_protmethod Write7BitEncodedInt

Writes a 32-bit integer in a compressed format.

NameDescription
System_CAPS_pubfield System_CAPS_static Null

Specifies a BinaryWriter with no backing store.

System_CAPS_protfield OutStream

Holds the underlying stream.

The BinaryWriter class provides methods that simplify writing primitive data types to a stream. For example, you can use the Write method to write a Boolean value to the stream as a one-byte value. The class includes write methods that support different data types.

When you create a new instance of the BinaryWriter class, you provide the stream to write to, and optionally specify the type of encoding and whether to leave the stream open after disposing the BinaryWriter object. If you do not specify an encoding type, UTF-8 is used.

System_CAPS_importantImportant

This type implements the IDisposable interface. When you have finished using the type, you should dispose of it either directly or indirectly. To dispose of the type directly, call its Dispose method in a try/catch block. To dispose of it indirectly, use a language construct such as using (in C#) or Using (in Visual Basic). For more information, see the “Using an Object that Implements IDisposable” section in the IDisposable interface topic.

A derived class can override the methods of this class to give unique character encodings.

The following code example demonstrates how to store and retrieve application settings in a file.

using System;
using System.IO;

class ConsoleApplication
{
    const string fileName = "AppSettings.dat";

    static void Main()
    {
        WriteDefaultValues();
        DisplayValues();
    }

    public static void WriteDefaultValues()
    {
        using (BinaryWriter writer = new BinaryWriter(File.Open(fileName, FileMode.Create)))
        {
            writer.Write(1.250F);
            writer.Write(@"c:\Temp");
            writer.Write(10);
            writer.Write(true);
        }
    }

    public static void DisplayValues()
    {
        float aspectRatio;
        string tempDirectory;
        int autoSaveTime;
        bool showStatusBar;

        if (File.Exists(fileName))
        {
            using (BinaryReader reader = new BinaryReader(File.Open(fileName, FileMode.Open)))
            {
                aspectRatio = reader.ReadSingle();
                tempDirectory = reader.ReadString();
                autoSaveTime = reader.ReadInt32();
                showStatusBar = reader.ReadBoolean();
            }

            Console.WriteLine("Aspect ratio set to: " + aspectRatio);
            Console.WriteLine("Temp directory is: " + tempDirectory);
            Console.WriteLine("Auto save time set to: " + autoSaveTime);
            Console.WriteLine("Show status bar: " + showStatusBar);
        }
    }
}
Imports System.IO

Module Module1
    Const fileName As String = "AppSettings.dat"

    Sub Main()
        WriteDefaultValues()
        DisplayValues()
    End Sub

    Sub WriteDefaultValues()
        Using writer As BinaryWriter = New BinaryWriter(File.Open(fileName, FileMode.Create))
            writer.Write(1.25F)
            writer.Write("c:\Temp")
            writer.Write(10)
            writer.Write(True)
        End Using
    End Sub

    Sub DisplayValues()
        Dim aspectRatio As Single
        Dim tempDirectory As String
        Dim autoSaveTime As Integer
        Dim showStatusBar As Boolean

        If (File.Exists(fileName)) Then

            Using reader As BinaryReader = New BinaryReader(File.Open(fileName, FileMode.Open))
                aspectRatio = reader.ReadSingle()
                tempDirectory = reader.ReadString()
                autoSaveTime = reader.ReadInt32()
                showStatusBar = reader.ReadBoolean()
            End Using

            Console.WriteLine("Aspect ratio set to: " & aspectRatio)
            Console.WriteLine("Temp directory is: " & tempDirectory)
            Console.WriteLine("Auto save time set to: " & autoSaveTime)
            Console.WriteLine("Show status bar: " & showStatusBar)
        End If
    End Sub

End Module
Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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